ARLINGTON — State environmental officials reaffirmed Thursday that they have no plans to add new control measures to clean up North Texas air, insisting that air quality will meet federal standards by 2018.
Members of the Texas Commission on Environmental Quality staff told the North Texas Clean Air Steering Committee that new federal standards for cleaner gasoline and “fleet turnover” — more North Texans trading in old cars for new, cleaner cars — would be enough to see a drastic improvement in the region’s poor air quality over the next three years.
The state’s announcement came after the presentation of two scientific studies on the effect of Barnett Shale gas production during a well-attended regional meeting on air quality and was met with some skepticism. State Rep. Lon Burnam, D-Fort Worth, said the lack of new controls really concerned him.
“It’s very short-sighted,” Burnam said.
North Texas has not been able to meet the federal clean air standard since it was implemented in 1997. It took about 10 years for ozone averages at the Denton Enterprise Airport monitor to drop from about 97 parts per billion to 87 ppb.
Even though the state had predicted that between 2010 and 2013, the ozone averages would drop another 10 ppb, progress has essentially stalled over the past five years.
This year, the state must also include Wise County in its plan to clean up North Texas air, the first time the predominantly rural county is included with the nine other counties in the non-attainment region. Nationwide, only Southern California, Houston and Baltimore have logged worse ozone averages than the Dallas-Fort Worth area in the past three years.
The Clean Air Act contains enforcement measures with economic implications beyond fines. In 2010, the Environmental Protection Agency revoked some of Texas’ air quality permits and required businesses to work directly with the federal agency.
State officials have not budged from the prediction they made in November that ozone levels in the region will drop to 76 ppb to meet a new, stricter federal standard.
Long-term ozone exposure has been linked to an increased risk of premature death from respiratory causes and ischemic heart disease. Ground-level ozone is made when volatile organic compounds, or VOCs, and nitrogen oxides combine in sunlight. In North Texas, most ozone tends to form in the warmer months during hot, dry weather when the winds stagnate.
Kuruvilla John, an engineering professor at the University of North Texas, worked with engineering graduate student Mahdi Ahmadi to separate the effects of the weather on the ozone from the effects of human activities.
They told committee members that air monitoring sites surrounded by oil and gas production show different and possibly worsening ozone trends, particularly since 2008 on the region’s west side, than monitors on the east side, which are farther from wells.
They also found that ozone levels from February to November — the region’s ozone “off-season” — are also climbing up, although they aren’t high enough to violate federal standards.
John cautioned the committee that the work was preliminary, but would ultimately be submitted for peer-reviewed publication.
Chemical engineering professor David Allen reported on continuing studies he and others at the University of Texas have done measuring methane emissions at oil and gas production sites around the country, including the Barnett.
They found that new federal control measures beginning in 2015 to control methane emissions during initial flowback of a new or reworked gas well — which has implications for VOC emissions — should reduce emissions more than previously thought.
But fugitive emissions for other kinds of equipment have been “substantially underestimated,” Allen said.
Allen told the committee that his group used some of the measurements from their study to test whether they can help improve predictions about local air quality. They found that adjusting for the underestimated emissions helped make better predictions.
The state uses estimates of all kinds of emissions, including estimates from power plants, cement plants, vehicle emissions and Barnett Shale gas production equipment, to predict whether the region’s air will improve, TCEQ staff said.
Whether the state uses any of this new knowledge to improve its predictions of North Texas air remains to be seen.
State officials told the committee that they would be finishing their prediction model this summer, when the committee is expected to meet again. The Texas Commission on Environmental Quality is expected to hold public hearings in January on its latest plan to clean up North Texas air.
PEGGY HEINKEL-WOLFE can be reached at 940-566-6881.